U.S. patent application number 13/068797 was filed with the patent office on 2011-11-24 for electroformed cornercube retroreflector.
Invention is credited to William O. Hubbs, Berl Stein.
Application Number | 20110284384 13/068797 |
Document ID | / |
Family ID | 44971563 |
Filed Date | 2011-11-24 |
United States Patent
Application |
20110284384 |
Kind Code |
A1 |
Hubbs; William O. ; et
al. |
November 24, 2011 |
Electroformed cornercube retroreflector
Abstract
An electroformed cornercube retroreflector, wherein a conductive
mandrel locates within an electrolyte containing metallic solution
and through charging of the mandrel located within the solution
attains electrodepositing of the metallic solution on to the
mandrel for the purpose of plating a thick coating of the metal
upon the mandrel. When the coating has achieved sufficient
structural integrity to form a cornercube retroreflector, it is
removed from the electrolyte, the deposited metal is separated or
stripped from the mandrel to provide a natural highly inner
polished metallic cornercube that can be placed within a partial
sphere or other supportive body for use as a retroreflector for
application for laser tracking in industrial or other
applications.
Inventors: |
Hubbs; William O.; (Cedar
Hill, MO) ; Stein; Berl; (Pittsford, NY) |
Family ID: |
44971563 |
Appl. No.: |
13/068797 |
Filed: |
May 20, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61396226 |
May 24, 2010 |
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Current U.S.
Class: |
205/50 ;
205/71 |
Current CPC
Class: |
C25D 1/06 20130101; G02B
5/122 20130101 |
Class at
Publication: |
205/50 ;
205/71 |
International
Class: |
C25D 1/06 20060101
C25D001/06 |
Claims
1. A method for forming an electroformed cornercube retroreflector,
including locating a mandrel having a tip end representing the mold
for electroplating a metallic cornercube thereon, placing said
mandrel into an electrolyte containing in solution of the metal to
be electroplated thereon, electroforming a cornercube onto the tip
end of said mandrel within said electrolyte, until such time as a
metallic cornercube has been formed having structural rigidity and
integrity, striping the electroformed corner cube from the mandrel,
and applying said cornercube precisely within a partial sphere to
create a Spherically Mounted Retroreflector or other supportive
body for use for laser tracking.
2. An electroformed corner cube retroreflector, including providing
a mandrel having a tip end representative of the shaped cornercube
desired to be electroformed, forming the cornercube on the mandrel
within an electrolytic process, said cornercube having a thickness
of approximately fifteen thousands of an inch, more or less as
required, removing the electroformed cornercube from the mandrel,
adhering the formed cornercube within a partial sphere to create a
Spherically Mounted Retroreflector or other supportive body, the
formed cornercube having a natural highly reflective surface
internally thereof and which is capable of reflecting a laser
during laser tracking in an industrial application.
3. An electroformed cornercube of claim 2, and having three
non-reflective surfaces that lie in sequence between the three
reflective mirror like surfaces.
4. An electroformed cornercube, of claim 2, and having three
non-reflective surfaces that are minimally tapered to assist in the
separation of the electroform from the mandrel tip.
5. A method for forming an electroformed cornercube, whereby the
inverse of production is provided, by the duplication of a male
mandrel for duplication of production efforts, from the female
electroformed cornercube.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This non provisional patent application claims priority to
the provisional patent application having Ser. No. 61/396,226
having filing date May 24, 2010.
FIELD OF THE INVENTION
[0002] This invention relates to the forming of a cornercube
retroreflector for use in laser tracking, and more particularly,
provides both a method and article for forming a cornercube from
the electroforming process, by depositing through electrolytic
action a metallic layer upon a mandrel(s) until such time as
sufficient metal thickness forms a cornercube of integral
structural integrity when removed from the mandrel for locating
within a partial spherical body to create a Spherically Mounted
Retroreflector (SMR) or other supportive body mounting designs as
required, for use in laser tracking in industrial applications.
BACKGROUND OF THE INVENTION
[0003] Cornercubes are applied or formed within a reflecting
chamber normally have three mutually orthogonal surfaces, and are
located within a cylinder, as an example, or within a partial
spherical body, and have been manufactured and used for some time.
For example, in the prior art, it has been known to place glass or
related material reflecting surfaces, normally three blended
surfaces into a triangular form within a sphere, to function as the
reflective surface for diverting a laser beam back to its source
for precision placement of machining components, tooling, or other
parts to be worked or to inspect for quality. The efforts required
to form that type of a retroreflector requires one highly skilled
in the art, to attain the proper placement of reflective surfaces
perpendicular to each other, and then to mount the glass assembly
precisely within the sphere, having the inner apex of the three
optically flat reflective surfaces located precisely at the center
of the formed partial sphere. These types of spheres can readily be
seen within the prior art patents obtained by one of the co
inventors herein, such as to be seen in the U.S. Pat. No.
7,110,194, in addition to the SMR shown in his U.S. Pat. No.
7,204,024.
[0004] Other patents showing related SMR'S can be seen in the U.S.
Pat. No. 6,299,122, disclosing a spherically mounted retroreflector
edge adaptor.
[0005] The co-inventor of this current invention has also designed
a displacement process for forming a hollow surveying
retroreflector reflecting chamber. This can be seen in the U.S.
Pat. No. 7,014,325. In that patent, the malleable material is
placed beneath a punch, and the punch itself is applied by pressure
within the malleable material, in order to form a cubecorner
configuration, that is used to form a reflecting chamber, by
pressure, within the material, and having the three mutually
orthogonal surfaces that are formed within the cylinder. Then, the
reflecting chamber within the cylinder can be used for reflecting
the laser, or it may be applied within a partial sphere, to form
the Spherically Mounted Retroreflector for use for laser tracking
purposes.
[0006] The concept of electroforming has been around for over a
century. For example, as known, electroforming has been used for
precision replication of fine-featured items, such as coins and
bank note printing plates, along with other jewelry, and artistic
products. Usually, electroforming is done upon a conductive
surface. If the surface to be coated is nonconductive, then usually
some form of a conductive paint, or other conductive coating, is
applied to the nonconductive surface, to provide a conductive
surface. As noted, electroforming, as a process, adds metal, atom
by atom, to the conductive surface, until it builds up to a
sufficient layer, normally having sufficient structural integrity
through the application of its thick layer of deposited metal, so
that the finished item is self-supporting.
[0007] The concept of this current invention is to combine the
concept of forming a cornercube retroreflector, through the metal
forming process, then to add it to a partial spherical body, in a
precise manner, so that the partial sphere and cornercube assembly
can be adapted for use and mounted for laser tracking purposes.
SUMMARY OF THE INVENTION
[0008] The concept of this invention primarily relates to
electroforming, and more specifically for use of a mandrel that has
the male components for forming precisely a cornercube for use in a
Spherically Mounted Retroreflector or other supportive body.
[0009] Electroforming is a metal forming process that uses
electrodeposition to plate the base form, know as the mandrel,
which is removed after plating. Technically, it is a process of
synthesizing a metal object by controlling the electrodeposition of
metal passing through an electrolytic solution onto a metal or
metallized form. More simply, a metal skin is built up on a metal
surface, or any surface that has been rendered conductive through
the application of a specialized paint, that contains metal
particles, or metallic vapor deposition, to make the surface
conductive. Essentially, a metal part is fabricated from the
plating process itself.
[0010] This differs from electroplating basically because the skin
is much thicker and can exist as a self supporting structure if the
original matrix, or mandrel, is removed. The object being
electroformed on can be a permanent part of the end product or can
be temporary, and removed later, leaving only the metal form, the
"electroform".
[0011] New technologies have made it possible for mandrels to be
very complex. In order to facilitate the removal of the
electroformed article from the mandrel, a mandrel is often made of
aluminum. Because aluminum can easily be chemically dissolved, a
complex electroform can be produced with near exactness.
[0012] In recent years, due to its ability to replicate a mandrel
surface precisely atom-by-atom with practically no loss of
fidelity, electroforming has taken on new importance in the
fabrication of micro and nano scale metallic devices and in
producing precision injection molds with micro and nano scale
feature for production of nonmetallic micro molded objects.
Electroforming tolerance of 1.5 to 3 nanometers has been reported
by some precision fabricators.
[0013] In the basic electroforming process, an electrolytic bath is
used to deposit nickel or other electroplatable metal onto a
conductive patterned surface, such as conductively coated glass or
other non-conductive material that has been conductively coated, or
normally conductive metallic materials such as stainless steel,
nickel, carbide and the like or any combination of the previously
suggested substrates. Once the plated material has been built up to
the desired thickness, the electroformed part is separated from the
master substrate. This process allows high-quality duplication of
the master and therefore permits quality production, at low unit
cost with high repeatability and excellent process control.
[0014] The main advantage of electroforming is that it reproduces
the external shape of the mandrel within 1 micrometer. Generally,
forming an internal cavity accurately is more difficult than
forming an external surface.
[0015] More specifically, with respect to forming a cornercube for
an item such as a Spherically Mounted Retroreflector, as noted in
the background discussion, such cornercubes hereto for have been
formed of usually glass prisms, three surfaces that mate in a
triangular orientation, in order to furnish the type of precise
reflective surface that allows for it to cooperate with the laser
beam, when performing laser tracking for precision setting or
measuring of various components or tooling. Then, the concept of
pressing a metal, such as lead, into the configuration of a
cornercube, was developed by one of the inventors herein, as to be
seen from a review of his U.S. Pat. No. 7,014,325.
[0016] If the mandrel used in the current invention is of metallic
composition, then normally it will have conducting characteristics,
and can be used in an electrolyte for achieving electroforming of a
cornercube. If a non-conducting mandrel is utilized in the process,
such as a glass, polymer, composite, ceramic or non-conductive
base, then it must be coated in such a way as to become conductive.
Nevertheless, regardless what type of mandrel is used, the process
yields a mirror bright finish, which in turn is representative of
the mirror bright finishes that are a part of the mandrel,
particularly where nickel may be used as the coating composition,
and which functions well in the formation of a cornercube, for
application into a Spherically Mounted Retroreflector or other
supportive body.
[0017] More specifically, this invention comprehends the usage of
an electroforming bath, and into which one or a plurality of
mandrels may be applied, the proper conducting charges may be
applied to each of these units, such as a positive connection to
the bath, that may contain nickel, or other depositable metals in
solution, and a negative charge may be applied to the mandrel, to
allow for the metal forming deposition. The mandrel is then
introduced into the bath, for some period of time, usually at least
twenty-four hours of submersion, or even up to five days, at which
time the metal forming process takes place, upon the tip of the
mandrel, which provides for its formation into a coating upon the
mandrel, for formation of the desired cornercubes. Usually, the
desirable result is to built up a coating of approximately fifteen
thousands of an inch, more or less, of nickel or other metal
deposition, and when that is achieved, the mandrel may be removed
from the bath, at which time one can readily observe the metal
forming applied at the tip of the mandrel, through the
electroplating process. At this point, the nickel alloy, that has
been applied to the male formed mandrel tip, that has the
appearance of a cornercube, with the metal formed nickel alloy
being removed, from the tip, and provides a very precise
cornercube, having a highly reflective and naturally polished inner
three triangulated surface, that is ready for application to a
partial sphere or other supportive body, for uses as a
retroreflector, in laser tracking applications. And, where it is
desired to form a series of the electroformed cornercubes, then a
plurality of mandrels may be applied to the supporting base, for
submersion within the electrolytic fluid, for creation of a series
of cornercubes, of precision dimensions, that can be readily
applied within their separate partial spheres to create a
Spherically Mounted Retroreflector or other supportive body, in
preparation for usage.
[0018] These are examples of the summary of the concept of this
invention, and how cornercubes can be formed by the identified
process, to precision dimensions, and ready for usage and
application in the further assembly of laser tracking
equipment.
[0019] It is, therefore, the principal object of this invention to
provide a means for electroforming of cornercubes for use and
installation within partial spheres to create Spherically Mounted
Retroreflectors or other supportive bodies, for application within
laser tracking procedures.
[0020] Still another object of this invention is to provide the
formation of cornercubes, that are of very precise and close
tolerances, so that they can be simply fitted within their
respective partial spheres to create Spherically Mounted
Retroreflectors or other supportive bodies, in preparation for
their usage.
[0021] A further object of this invention is to provide the
formation of cornercubes by the electroforming process.
[0022] Still another object of this invention is to provide a means
for forming, simultaneously, a series of cornercubes by the
electroforming process.
[0023] Furthermore, another object of the invention is to provide a
means of re-producing accurate male cornercube mandrel portions,
inversely, using the electroforming process, by replicating from an
electroformed female cornercube, thus allowing for the production
of mandrels using the electroforming process and thereby
multiplying production tooling using the same process.
[0024] These and other objects may become more apparent to those
skilled in the art upon review of the summary of the invention as
provided herein, and upon undertaking a study of the description of
its preferred embodiments, in view of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In referring to the drawings,
[0026] FIG. 1 provides a view of the electroforming reservoir,
containing its electrolyte, and showing its mounted mandrel ready
for submersion into the electrolyte for electroforming of a
cornercube;
[0027] FIG. 2 shows the mounted mandrel submerged within the
electrolytic solution during the electroforming process;
[0028] FIG. 3 shows the mounted mandrel elevated from the solution,
disclosing upon its tip an electroformed cornercube;
[0029] FIG. 4 shows the supported mandrel with its electroformed
cornercube having been separated from formed tip of the shown
mandrel;
[0030] FIG. 5 shows a formed cornercube of this invention, in this
particular instance, being fabricated of a nickel metal;
[0031] FIG. 6 shows another view of the formed cornercube;
[0032] FIG. 7 shows a plurality of mandrels being supported by its
upper mount and being positioned within the solution of the
container, during performance of an electroforming process;
[0033] FIG. 8 shows the mounted mandrels elevated, at the
completion of an electroforming process, having a series of
cornercubes formed upon the tips of the mandrels;
[0034] FIG. 9 shows a formed cornercube that has been located
within a partial sphere to create a spherically mounted
retroreflector, in preparation for laser tracking usage; and
[0035] FIG. 10 shows the cornercube of this invention mounted
within a Spherically Mounted Retroreflector, and resting upon its
sphere mount as during usage and application.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] In referring to the drawings, and in particular FIG. 1, the
equipment utilized in electroforming of the cornercubes of the
current invention is readily disclosed. As to be seen, it includes
a vessel 1 that contains a supply of the electrolyte 2, which, as
is well know, forms a liquid ionic conductor that provides for the
movement of ions, which in the preferred case, a solution of nickel
that transmits by electrolysis to the precisely formed tip 3 of the
mandrel 4 that is supported by its mount 5 when ready for
performing the electroforming process. Obviously, other
electrolytes can be used, in the electroforming process, and it
could use such metals as copper, gold, and other decorative metals
such as platinum, rhodium, or even silver, but in this particular
industrial application, nickel plating has been found most
effective. The liquid ionic conductor utilized may include any
substance such as a salt, or acid, when dissolved in a suitable
solvent, such as water, and which functions as a carrier for the
metallic ions, which when subjected to electrical charge, produces
the electroforming upon the tip 3 of the mandrel, as can be
understood.
[0037] Usually, in the electroforming process, it may take
approximately one to five days to achieve the thickness of
electroforming as desired for the cornercube, and it has been found
that a cornercube formed of approximately fifteen thousands of an
inch, more or less, has sufficient structural integrity to allow
its use within a Spherically Mounted Retroreflector or other
supportive body, for laser tracking purposes.
[0038] While the mandrel of this invention may be formed of a
metal, and therefore is receptive to conductive charge, and for
achieving electroforming thereon, other types of materials could be
used, such as glass, polymer, or the like, and which may be coated
with a conductive paint, or metallic vapor deposition, in order to
attain the electroforming attributes of this invention.
[0039] More specifically, in the basic electroforming process, an
electrolytic bath is used to deposit the nickel, or other
electroplatable metal, onto a conductive patterned surface, such as
the tip 3 of the mandrel herein, or it may be coated onto glass, or
stainless steel, the former including a coating of metallized
paint, or metallic vapor deposition. Once the plated material has
built up to its desired and required thickness, such as the fifteen
thousands of an inch, as a forth set, the electroformed part is
stripped off of the master substrate, in this instance, being the
tip of the mandrel 4. This process allows high quality duplication
of the master, and therefore permits quality production of the
cornercube, at low unit cost, with high repeatability and excellent
process control, in the performance of its process.
[0040] FIG. 2 shows the performance of the process of this
invention wherein the base supported mandrel 4 has its precisely
formed tip immersed within the electrolyte 2, during the procedure
of electroforming of the cornercubes of this invention. As
previously stated, it may take as many as three to five days to
build up the integrity of the forming cornercube, so that attains
that desired structural thickness within the range of about that
fifteen thousands of an inch, more or less.
[0041] When it has been determined that the formed cornercube has
achieved its desired thickness, and strength, the base supported
mandrel 4 is removed from the bath. As to be seen in FIG. 3, the
electroformed tip 6 is deposited onto the contoured lowered tip of
the shown mandrel, and is ready to be separated in a linear motion,
as to be noted in FIG. 4, and is ready for its preparation for
application to a partial sphere to create a Spherically Mounted
Retroreflector or other supportive body. Since the precision
electroforming has formed the cornercube to precise dimensions, and
its critical internal mirror like surfaces will be formed to micro
dimensions, the entire formed cube is ready for application into
the counterbore of a partial sphere or other supportive body, which
may be adhesively applied therein, and ready for usage in the laser
tracking process.
[0042] FIG. 5, in addition to FIG. 6, shows the electroformed
cornercube 6, and it can be seen that its peripheral thickness is
formed of some degree of structural strength, as noted at 7, and
which may be within that range of approximately fifteen thousands
of an inch, more or less as required which provides sufficient
structural integrity against its bending or warping, as it is
adhesively or otherwise applied or connected into the sphere, in
preparation for its usage. As can also be seen, and due to the
nickel plating of the formed cornercube upon the mandrel, the three
internal surfaces 8, 9, and the third surface (not shown) forms a
triangulated series of surfaces that are highly polished simply due
to their electroforming, and ready for use for reflective purposes,
for the transmission of the laser beam, as applied during the laser
tracking process, in industrial applications. FIG. 6 shows the
relative size of this particular formed cornercube 6, although
there are size options, after it has been separated in a linear
motion from the mandrel 4.
[0043] As to be noted in FIG. 7, a plurality of mandrels 10 can be
stably supported from its mount 11 and ready for deposition within
the electrolyte 12 of the vessel 13. This shows how a plurality of
the cornercubes can be formed, simultaneously, during the
manufacturing process, and immediately ready for application, once
formed, into their respective spheres, when the Spherically Mounted
Retroreflectors are prepared for marketing and industrial
applications. FIG. 8 shows the plurality of mandrels 10 as elevated
from the electrolytic bath, and showing how their lower tips
contain the formed cornercubes 14 ready for stripping and further
processing when applied to partial spheres to create a Spherically
Mounted Retroreflector. The only really time consuming feature of
forming cornercube retroreflectors in this manner is the time delay
in the electroforming process, but since the procedure is extremely
accurate in forming very close tolerance cornercubes, and since no
man power is necessary during the electroforming process, this does
not add any significant cost to the construction of the structured
spheres, for use for laser tracking purposes.
[0044] FIGS. 9 and 10 show a Spherically Mounted Retroreflector
(SMR) 15 where the electroformed cornercube 16 has been applied
within a counterbore within the sphere, which is now readied for
application within the sphere mount, as at 17, when applied in a
laser tracking operation. See FIG. 10. The naturally formed
reflective surfaces 18 can be readily seen within the cornercube,
and these are simply formed through the electroforming process,
they are a highly reflective, mirror like surface without any
further polishing procedure being necessary, simply because of the
electroforming method, that applies the nickel metal to the surface
of the tip of the mandrel, during and through usage of the
electroplating and electroforming process. The naturally formed
surfaces, 3 places, 19 that lie in sequence between the 3
reflective mirrors like surfaces, are dull and non-reflective.
These 3 surfaces are also minimally tapered to assist in the
separation of the electroformed cornercube from the mandrel tip.
The formed cornercubes 16 are immediately ready for application and
usage, for connection within the counterbore of the partial
spherical body, immediately after they are stripped from the
mandrel.
[0045] Variations or modifications to the subject matter of this
electroforming invention may occur to those skilled in the art upon
review of the summary of the invention as provided herein, and upon
undertaking a study of the description of its preferred embodiment.
Such variations, within the spirit of this invention, are intended
to be encompassed within the scope of any claims to patent
protection issuing hereon. The description of the preferred
embodiment, and the disclosure of the invention within the
drawings, is done so for illustrative purposes only.
* * * * *